Mechanism for actuating thread twisting means in looms



April 27, 1954 I E. PFARRWALLER 2,676,618

MECHANISM FOR ACTUATING THREAD TWISTING MEANS IN LOOMS Filed Aug. 5,1950 INVENTQR ATTORNEY Patented Apr. 27, 1954 OFFICE MECHANISM FORACTUATING THREAD TWISTING MEANS IN LOOMS Erwin Pfarrwaller, Winterthur,Switzerland Application August 5, 1950, Serial No. 1775787 6 Claims.

The present invention relates to an improved mechanism for actuatingshedding cards and more particularly thread twisting means inlooms forweaving.

The present application is a continuation-inpart of my co-pendingapplication, Serial No. 12,948, filed March 4, 1948, which matured onJuly 8, 1952, into Patent No. 2,602,470.

It is an object of the invention to provide a mechanism for twistingwarp threads in a loom for weaving by means of cards preferably havingthe configuration of rings with teeth on their circumferences which meshwith teeth of pinions which are rotated for actuating the cards. Thepresent invention is particularly directed toward an improved drivingmechanism for operating the aforesaid pinions to produce apre-determined pattern of motions of the twisting rings.

The mechanism according to the invention comprises a shaft which iscontinuously rotated,

preferably by the same source of power which operates the loom, camshaving a plurality of individual active surface portions and beinpreferably exchangeably mounted on said shaft for producing the desiredpattern of movement of the pinions and twisting rings, and operatingmeans comprising cam. followers engaging said cams and means connectedwith said cam followers a-nd operatively connected with said pinions formoving the twisting rings in consecutive steps in accordance with theconfiguration of said cams. The aforementioned operating meanspreferably comprise a bellcrank leverlike member having a cam followeron each arm, said followers individually engaging the surfaces of a pairof like cams fixed on the aforementioned shaftin offset relation, andvhaving a toothed surface on one arm engaging a pinion which isconcentrically fixed to a gear wheel having teeth meshing with those ofone of said pinions. The same pair of cams may be engaged by a secondbellcrank lever which operates a second card disc through a second trainof gears. Instead of providing two followers and two cams, each levermay have only one follower actuated by one cam, the cam being in theform of a groove receiving the follower or the follower may be pressedto the by the action of a spring connected with the lever and astationary part of the loom.

Such arrangements are conventional and their use no departure from thescope of the present invention.

The mechanism according to the invention does nct require means fortranslating the continuous rotation of a shaft, which may be rotated bythe loom drive, into an intermittent rotation-of another shaft, althoughit may be modifled to embody such means.

The cams preferably have surface portions between motion producingportions for suspending motion of the twisting means between successiveactuations during desired periods of time.

The mechanism according to the invention is primarily for the purpose oftwisting adjacent warp threads for binding weft threads, for example, atthe edge of a fabric for producing a border. According to the design ofthe cams, the direction of twist may be reversed after each or aplurality of twists and, by interposing circular cam portions concentricwith the axis of rotation of the cams between motion producing camportions, operation of the twisting means can be suspended after eachtwist for a pre-determined duration. By proper design of the cams, thisduration may, for example, after a desired number of twistingoperations, be so great as to permit several weft insertions beforemaking the next twist. By using appropriately shaped cams, a greatvariety of binding patterns can be obtained.

Further and other objects of the present invention will be hereinafterset forth in the accompanying. specification and claims, and are shownin the drawings which, by way of illustration, show what I now considerto be preferred embodiments of the invention.

In the drawings:

Fig. 1 is a diagrammatic side elevation of a loom provided with a warpthread twisting mechanism according to the invention, but not showingthe actuating means for the twisting mechanism.

Fig; 2 is a large scale side view, partly in section, of a, mechanismaccording to the invention for actuating the twisting discs or rings;

Fig. 3 is a view in axial direction of a pair of cams forming part ofthe mechanism according to Fig. 2;

Fig. 4 is a diagrammatic showing of warp threads twisted about weftthreads in a pattern produced by the cams shown in Fig. 3;

Fig. 5 is a View in axial direction of a pair of cams shaped differentlyfrom those shown in Fig. 3 for producing the pattern illustrated in '7vis a large scale view of a portion of one cam of the pair shown in Fig.5;

Fig. 8 is a view in axial direction of a further modification of a campair for producing the pattern shown in Fig. 9.

Like parts are designated by like numerals in all figures of thedrawings.

As shown in Fig. l, the warp threads 1 move from warp beam 6 over atensioning beam 20 where they separate to form an upper shed 2| and alower shed 22, through eyes 24 of the heddles I0, and reed 25 to theapex 26 of the shed where they form the fabric 9 by interlacing with theweft threads I8. The fabric passes over a guide beam 21 and is thenwound on a fabric beam 8.

Binding threads 28 and 29 move from spools 30 and 3| over the tensioningbeam 20, individually through eyes 33 and 34 of a twisting ring 35,through the read 25, and to the apex 2B of the shed, wherefrom they arewound, intertwined with fabric 9, on the beam 8.

The twisting rings 35 are supported in a frame 31. The rings areprovided with teeth 38 and individually engage the teeth of pinions 39and 40 which are keyed to shafts 4| and 42, respectively.

Fig. 2 illustrates a mechanism according to the invention for actuatingthe shafts 4| and 42 for producing the desired warp thread twistingpattern. Elbow r bellcrank levers I 50 and I each having two arms, arepositively oscillated about stationary pins I54 and I55, respectively,in the direction of double arrows I55, I51 by means of substantiallycircular cams 200 and 20I which are eccentrically mounted on shaft I 45and respectively engaged by rollers I65 and IE6 on lever I 50 androllers I61 and I68 on lever I5I. The oscillating movement of levers I50and I5I is transferred by the toothed end portions I58, and I59,respectively, of the upright arms of the levers to double tooth wheelsI60, I5! and I92, I63, respectively, and therefrom to pinions I 2| andI22, respectively, on shafts 4| and 42. Shaft I45 may be drivenintermittently in the direction of arrow I23 by a Geneva gear as shownin Patent No. 2,602,470. Shaft I45 may also be driven continuously, forexample by the loom drive, which also drives the picking mechanism.

In the operating position shown in Fig. 2, lever I5I changes itsmovement from that indicated by arrow I69 to that of arrow I whereby therotation of shaft 42 is reversed from arrow I 1| to I12. Lever I50 movesin the direction of arrow I13 and shaft 4| rotates in the direction. ofarrow I14. Due to the relatively displaced positions of levers I50 and I5| reversal of rotation of shafts 4| and 42 does not occur at the sametime.

If shaft I45 is driven continuously in the same direction of rotation,cam discs 200 and must be provided with active cam surfaces composed ofa plurality of individual curve portions. Figures 3, 5, 8 illustratethree differently shaped cam pairs for producing difierent twistingpatterns. The individual cam portions which pro-' duce catuations of thetwisting discs or rings are separated in Figures 3, 5, 'i', 8 by radiallines a to n. The mechanism is at a standstill whenever the camfollowers I65, I66 and I61, I68 reach a portion of the cam surfaceadjacent to the in' portion, the elbow levers I50 and I5I make par tialswings, depending on the length of the cam portion between two radiallines and the gear wheels I60, I6I and I62, I63 are rotated and effectrotation of shafts 4| and 42, respectively.

With a configuration of the cam discs 200 and MI as shown in Fig. 3, thecard discs 35 are rotatecl through 180 when shaft I rotates through anangle between any two consecutive radii a. to n.

Fig. 4 is a diagram indicating the twisting pattern produced by the camsshown in Fig. 3. Twisting is reversed after six actuations of a twistingring, when an elbow lever is actuated by a cam portion of smallestradial extent, as at radius a, and by a cam portion of greatest radius,as at 9. At these points, direction of the swinging direction of theelbow levers is reversed. The surface of the cam traversing radial linesa, b, c, d, e, f 9 is symmetrical to the surface traversing lines a, n,m, k, h, g.

When using cams as shown in Fig. 3, two warp threads are twisted aboutone another and, if the operation of the twisting mechanism isappropriately coordinated with that of the pick ing mechanism of theloom, about a weft thread at each angular movement of shaft I 45 fromone radial line to the next following radial line.

By using cam discs of a configuration illustrated in Fig. 5 anddesignated by numerals 202 and 203, a twisting pattern will be obtainedas shown diagrammatically in Fig. 6. In this pattern, twisting issuspended while the cam shaft I 45 moves from radius 0 to radius b andfrom radius 2' to radius h and, since the speed of shaft I45 iscoordinated with that of the picking mechanism, two weft threads I8 willbe bound between two consecutive twists of the warp threads. Fig. 7illustrates a portion of cam disc 202 on a larger scale. When roller I65abuts the arcuate surface 206 of disc 202 at radius 1, lever I remainsat rest until the roller rides up on the cam surface 208 between points201 and 209, causing clockwise movement of lever I50. A cylindrical camsurface portion 2I0 begins at point 209 and extends to point 2 I Isymmetrically to radius 9. This cylindrical surface suspends movement oflever I50 and actuation of the card disc associated therewith. Adescending portion 2I2 of the cam curve begins at point 2H and continuesat point 2I3 into a circular portion 2 I4 at radius h which portion endsat point 2I5 beyond radius i. This extended circular portion suspendsactuation of a twisting ring during the period when shaft I45 movesthrough the angle enclosed by radii h and i. Thereafter roller I ridesdown on cam curve portion 2|6 until it reaches point 2I1 ahead at radiusis thereby causing a second partial swing of the lever actuated by thecam, this second partial swing having the same direction as the first.partial swing caused by the cam portion 2I2. After a standstill alongcircular cam curve portion 2|8. the roller rides down further, or inwardas seen in Fig. 2, along cam portion 220 between points 2I9 and 22I,causing the actuated lever to make a third partial swing in the samedirection as the first two partial swings. The same happens betweenradii m and n and n and a, as seen in Fig. 5. The twisting rings arerotated through upon each partial swing of the respective levers. therotation being not reversed as long as a cam follower rides on the camportions indicated by radii ato g. The swing direction of the leverisreversed at radius g and continues, stepwise, in the reversed directionwhen the cam follower rides along the cam portions confined betweenradii 9', h, i, k, m, n, and a. At a the swing motion of the lever isagain reversed.

By exchange and use of different cam discs, any pattern of intertwiningmay be produced. For example, by using cams as shown in Fig. 8, two weftthreads may be inserted between twists of difierent directions. This isdiagrammatically illustrated in Fig. 9, where the twist is reversed notat g, as in Figs. 4 and 6, but at z. According to this pattern, two weftthreads are intertwined between two consecutive twists, and there areonly four twists between changes of direction of twist. If only one weftthread were bound in between two consecutive twists, the warp threadswould be twisted eight times in one direction before they were twistedin the opposite direction. With the cams shown in Fig. 8, an interval ispermitted between consecutive twists in the same, as well as in theopposite, direction. It will be noted that in the pattern according toFig. 4, the direction of twist is reversed after six twists.

Though the provision of cylindrical portions at the intersections of thecam curve with the radii a to n is desirable, the device would operatealso if no such portions were arranged between the active cam surfaceportions. The eyes 33 and 34 of the twist rings hold the shed open longenough to permit insertion of a weft thread also if no specialprovisions are made for extending the time during which the shed is wideopen.

A considerable advantage of the present invention is that it adapts theweave construction of the twisted threads to the weave construction ofthe fabric. The distance of the weft thread in the small twisted selvagemust be chosen in accordance with the character of the fabric,especially for loose woven patterns like tulle, in that the edge is notto be stiffer than the fabric. A further advantage is that by adaptingthe weave constructions of both fabric and selvage the length of thetwisted warp threads is kept the same as the length of the other warpthreads, so that the twisted threads do not need special bobbins but maybe wound on the warp beam.

While I believe the above described embodiments of my invention to bepreferred embodiments, I wish it to be understood that I do not desireto be limited to the exact details of method, design and constructionshown and described, for obvious modifications will occur to a personskilled in the art.

I claim:

1. In a 100m the combination of a continuously rotating shaft, threadtwisting means, operating means connecting said shaft and said twistingmeans for rotating the twisting means stepwise in either direction; saidoperating means comprising a bellcrank lever, a cam follower fixed toeach arm of said lever, pairs of substantially like cam members fixed onsaid shaft, one cam member of each pair engaging one cam follower andthe other cam member engaging the other cam follower, said cam membershaving a series of active cam surface portions actuating said lever inconsecutive steps, and a mechanism interconnectin said lever and saidtwisting means for transmitting the motions of said lever to saidtwisting means.

2. A mechanism for actuating thread twisting means in looms comprising aplurality of rotatable twisting members, a continuously rotating shaft,a pair of cams fixed on said shaft, each cam having a series ofindividual consecutively effective cam surface portions, a lever foreach cam, said levers being engaged by said cams and individuallystepwisely actuated by said surface portions to make partial swings uponrotation of the cams through an angle substantially corresponding to oneof said surface portions, and a plurality of motion transmitting meansindividually interconnecting said levers and said members for rotationof the latter upon each partial swing of the respective lever andreversing the direction of rotation of said members upon reversal of theswinging direction of said levers.

3. A mechanism as defined in claim 2, said levers having theconfiguration of bellcranks individually engaging said cams with onearm, said motion transmitting means being individually connected to theother arms of said bellcrank levers.

4. A mechanism as defined in claim 2, said cams having cylindricalsurface portions concentrio with the rotation axis of the cams andindividually disposed between two consecutive cam surface portions forsuspending actuation of the respective levers between actuations by saidcam surface portions.

5. A mechanism as defined in claim 2, said cams individually having twosymmetrically shaped and diametrically opposed sides, each side having aseries of consecutively acting individual surface portions.

6. A mechanism for actuating a rotatable thread guiding member in aloom, said mechanism comprising a shaft rotating continuously in onedirection, substantially circular cam means fixed eccentrically on saidshaft, a lever actuated by said cam means, said cam means having aseries of individual active cam portions for causing said lever to makea partial swing upon rotation of said cam means through an anglesubstantially corresponding to one of said surface portions, and amotion transmitting means interconnecting said lever and said member forrotation of the latter upon each partial swing of said lever andreversing the direction of rotation of said member upon reversal of theswinging directing of said lever.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 639,626 Steere Dec. 19, 1899 1,757,947 Snow May 6, 19302,083,291 Camps June 8, 1937 2,099,729 Floyd et a1. Nov. 23, 19372,399,880 Moessinger May 7, 1946 2,401,452 Banyai June 4, 1946

